A metagenome-level analysis of a microbial community fermenting ultra-filtered milk permeate

• DOI: 10.3389/fbioe.2023.1173656
• Publication Date: 2023-05-17T05:43:45Z
• Authors: Kevin A. Walters; Geethaanjali Mohan; Kevin S. Myers; Abel T. Ingle; Timothy J. Donohue; Daniel R. Noguera
• Keywords: Lactose permease

Fermentative microbial communities have the potential to serve as biocatalysts for conversion of low-value dairy coproducts into renewable chemicals, contributing a more sustainable global economy. To develop predictive tools design and operation industrially relevant strategies that utilize fermentative communities, there is need determine genomic features community members are characteristic accumulation different products. address this knowledge gap, we performed 282-day bioreactor experiment with was fed ultra-filtered milk permeate, coproduct from industry. The inoculated an acid-phase digester. A metagenomic analysis used assess dynamics, construct metagenome-assembled genomes (MAGs), evaluate lactose utilization fermentation product synthesis represented by assembled MAGs. This led us propose that, in reactor, Actinobacteriota phylum important degradation lactose, via Leloir pathway bifid shunt, production acetic, lactic, succinic acids. In addition, Firmicutes contribute chain-elongation-mediated butyric, hexanoic, octanoic acids, microbes using either ethanol, or lactic acid growth substrate. We conclude genes encoding carbohydrate pathways, transport cell, electron confurcating lactate dehydrogenase, its associated transfer flavoproteins, whose presence needs be established infer substrate chain elongation.